Composition for stretch hood, method of producing the same, and articles made therefrom

ABSTRACT

The instant invention provides a composition suitable for stretch hood, method of producing the same, and articles made therefrom. The article according to the present invention comprises a multi-layer film according to the present invention has a thickness of at least 3 mils comprising at least one inner layer and two exterior layers, wherein the inner layer comprises at least 50 weight percent polyethylene copolymer having a melt index less than 2 grams/10 minutes, a density less than or equal to 0.910 g/cm 3 , a total heat of fusion less than 120 Joules/gram and a heat of fusion above 115° C. of less than 5 Joules/gram, the total heat of fusion of the inner layer less than the heat of fusion of either of the two exterior layers, and wherein the multi-layer film has an elastic recovery of at least 40% when stretched to 100% elongation.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part application of theU.S. application Ser. No. 12/781,247, filed on May 17, 2010, entitled“STRETCH HOOD FILMS,” the teachings of which are incorporated byreference herein, as if reproduced in full hereinbelow, which claimspriority from the U.S. Provisional Application No. 61/222,371, filed onJul. 1, 2009, entitled “STRETCH HOOD FILMS,” the teachings of which areincorporated by reference herein, as if reproduced in full hereinbelow.

FIELD OF INVENTION

The instant invention relates to a composition suitable for stretchhood, method of producing the same, and articles made therefrom.

BACKGROUND OF THE INVENTION

There have been many varieties of polyethylene polymers polymerized overthe years, including those made using high pressure free radicalchemistry (LDPE), more traditional linear low density polyethylene(LLDPE) typically made using Ziegler-Natta catalysis and metallocene orconstrained geometry catalyzed polyethylene—some linear polyethylenes,but also some substantially linear polyethylene containing a slightamount of long chain branching. While these polymers have varyingpositives and negatives—depending on application or end-use—more controlover the polymer structure is still desired.

We have now found that post-metallocene catalysts can efficientlypolymerize ethylene into polymers and polymer compositions havingcontrolled comonomer distribution profiles, while also controllingunsaturation levels in the polymer and that multi-layer films comprisingsuch new polymers, especially when the new polymer comprises an innerlayer, are useful as stretch hood films. Stretch hood films are usefulin unitizing pallets of goods for shipment and transport.

SUMMARY OF THE INVENTION

The instant invention provides a composition suitable for stretch hood,method of producing the same, and articles made therefrom. In oneembodiment, the present invention provides an article comprising amulti-layer film having a thickness of at least 3 mils comprising atleast one inner layer and two exterior layers, wherein the inner layercomprises at least 50 weight percent polyethylene copolymer having amelt index less than 2 grams/10 minutes, a density less than or equal to0.910 g/cm³, a total heat of fusion less than 120 Joules/gram and a heatof fusion above 115° C. of less than Joules/gram, the total heat offusion of the inner layer less than the heat of fusion of either of thetwo exterior layers, and wherein the multi-layer film has an elasticrecovery of at least 40% when stretched to 100% elongation.

In an alternative embodiment, the present invention provides an articlecomprising a multi-layer film, as described above, wherein the exteriorlayers are less than 50 weight percent of the total film.

In another embodiment, the present invention provides an articlecomprising a multilayer film, as described above, wherein the film has 3layers and is made via blown film process.

In another alternative embodiment, the present invention provides anarticle comprising multilayer film, as described above, that is astretch hood film structure.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer in the inner layer has a molecular weightdistribution (M_(w)/M_(n)) of at least 2.5.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, wherein the polyethylene copolymerof the inner layer is characterized by a Comonomer Distribution Constant(CDC) greater than about 45 and as high as 400, and wherein thepolyethylene copolymer has less than 120 total unsaturationunit/1,000,000 carbons (C). CDC is defined as Comonomer DistributionIndex divided by Comonomer Distribution Shape Factor multiplying by 100(Equation 1, FIG. 1) Comonomer distribution index stands for the totalweight fraction of polymer chains with the comonomer content rangingfrom 0.5 of median comonomer content (C_(median)) and 1.5 of C_(median)from 35.0 to 119.0° C. Comonomer Distribution Shape Factor is defined asa ratio of the width at half peak height (HalfWidth) of comonomerdistribution profile divided by the standard deviation (Stdev) ofcomonomer distribution profile from the peak temperature (T_(p)).

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer of the inner layer is characterized by up toabout 3 long chain branches/1000 carbons.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer of the inner layer is further characterized ascomprising less than 20 vinylidene unsaturation unit/1,000,000 C.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer of the inner layer comprises a single DSC meltingpeak.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein themultilayer film has a normalized dart impact, measured according to DartB test (g/mil) (ASTM D-1709), in the range of from 350 g/mil to 700g/mil; for example, from 350 g/mil to 600 g/mil.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, there is shown in thedrawings a form that is exemplary; it being understood, however, thatthis invention is not limited to the precise arrangements andinstrumentalities shown.

FIG. 1-19 illustrate various corresponding Equations;

FIG. 20 illustrates chemical structure representations of unsaturations;

FIG. 21 illustrates the modified pulse sequences for unsaturation withBruker AVANCE 400 MHz spectrometer;

FIG. 21 displays integration limits for unsaturation a related inventivecomposition; the dash line means the position can be slightly differentdepends on the sample/catalyst;

FIG. 23 is a schematic drawing for obtaining peak temperature, halfwidth and median temperature from crystallization elution fractionation(CEF); and

FIG. 24 is a graph illustrating the relationship between dW/dT vs.temperature (° C.) from CEF data; and

FIG. 25 is a graph illustrating the relationship between Heat flow (W/g)versus temperature (° C.) generated from the 2^(nd) heat DSC data.

DETAILED DESCRIPTION OF THE INVENTION

The instant invention provides a composition suitable for stretch hood,method of producing the same, and articles made therefrom. In oneembodiment, the present invention provides an article comprising amulti-layer film having a thickness of at least 3 mils, for example,from 75 μm to 300 μm, or in the alternative, from 75 μm 150 μm,comprising at least one inner layer and two exterior layers, wherein theinner layer comprises at least 50 weight percent, for example, from 50to 100 weight percent, polyethylene copolymer having a melt index lessthan or equal to 2 grams/10 minutes, for example from 0.2 to 2 grams/10minutes, or in the alternative, from 0.2 to 1.5 grams/10 minutes, adensity less than or equal to 0.910 g/cm³, for example from 0.8602 lessthan or equal to 0.910 g/cm³, an total heat of fusion less than 120Joules/gram and a heat of fusion above 115° C. of less than 5Joules/gram, and the total heat of fusion of the inner layer less thanthe heat of fusion of either of the two exterior layers, and wherein themulti-layer film has an elastic recovery of at least 40 percent, forexample at least 42 percent, when stretched to 100 percent elongation.

In an alternative embodiment, the present invention provides an articlecomprising a multi-layer film, as described above, wherein the exteriorlayers are less than 50 weight percent of the total film.

In another embodiment, the present invention provides an articlecomprising a multilayer film, as described above, wherein the film has 3layers and is made via blown film process.

In another alternative embodiment, the present invention provides anarticle multilayer film, as described above, that is a stretch hood filmstructure.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer in the inner layer has a molecular weightdistribution (M_(w)/M_(n)) of at least 2.5, for example, from 2.5 to3.5.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, wherein the polyethylene copolymerof the inner layer is characterized by a Comonomer Distribution Constant(CDC) greater than about 45 and as high as 400, and wherein thepolyethylene copolymer has less than 120 total unsaturationunit/1,000,000 carbons (C). CDC is defined as Comonomer DistributionIndex divided by Comonomer Distribution Shape Factor multiplying by 100(Equation 1, FIG. 1) Comonomer distribution index stands for the totalweight fraction of polymer chains with the comonomer content rangingfrom 0.5 of median comonomer content (C_(median)) and 1.5 of C_(median)from 35.0 to 119.0° C. Comonomer Distribution Shape Factor is defined asa ratio of the width at half peak height (HalfWidth) of comonomerdistribution profile divided by the standard deviation (Stdev) ofcomonomer distribution profile from the peak temperature (T_(p)).

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer of the inner layer is characterized by up toabout 3 long chain branches/1000 carbons.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer of the inner layer is further characterized ascomprising less than 20 vinylidene unsaturation unit/1,000,000 C.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein thepolyethylene copolymer of the inner layer comprises a single DSC meltingpeak.

In another alternative embodiment, the present invention provides anarticle comprising a multilayer film, as described above, wherein themultilayer film has a normalized dart impact, measured according to DartB test (g/mil) (ASTM D-1709), in the range of from 350 g/mil to 700g/mil; for example, from 350 g/mil to 600 g/mil.

In some processes, processing aids, such as plasticizers, can also beincluded in the inventive ethylene-based polymer. These aids include,but are not limited to, the phthalates, such as dioctyl phthalate anddiisobutyl phthalate, natural oils such as lanolin, and paraffin,naphthenic and aromatic oils obtained from petroleum refining, andliquid resins from rosin or petroleum feedstocks. Exemplary classes ofoils useful as processing aids include white mineral oil such as KAYDOLoil (Chemtura Corp.; Middlebury, Conn.) and SHELLFLEX 371 naphthenic oil(Shell Lubricants; Houston, Tex.). Another suitable oil is TUFFLO oil(Lyondell Lubricants; Houston, Tex.).

In some processes, inventive ethylene-based polymers are treated withone or more stabilizers, for example, antioxidants, such as IRGANOX 1010and IRGAFOS 168 (Ciba Specialty Chemicals; Glattbrugg, Switzerland). Ingeneral, polymers are treated with one or more stabilizers before anextrusion or other melt processes. In other embodiment processes, otherpolymeric additives include, but are not limited to, ultraviolet lightabsorbers, antistatic agents, pigments, dyes, nucleating agents,fillers, slip agents, fire retardants, plasticizers, processing aids,lubricants, stabilizers, smoke inhibitors, viscosity control agents andanti-blocking agents. The inventive ethylene-based polymer compositionmay, for example, comprise less than 10 percent by the combined weightof one or more additives, based on the weight of the inventiveethylene-based polymer composition and such additives. A particularbenefit of the claimed polymers is the absence of catalyst kill agents,other than water, thus eliminating the need for calcium stearate.

The inventive ethylene-based polymer compositions produced may furtherbe compounded. In some embodiments, one or more antioxidants may furtherbe compounded into the inventive ethylene-based polymer compositions andthe compounded inventive ethylene-based polymer compositions is thenpelletized. The compounded ethylene-based polymer composition maycontain any amount of one or more antioxidants. For example, thecompounded inventive ethylene-based polymer compositions may comprisefrom about 200 to about 600 parts of one or more phenolic antioxidantsper one million parts of the inventive ethylene-based polymercompositions. In addition, the compounded ethylene-based polymercomposition may comprise from about 800 to about 1200 parts of aphosphite-based antioxidant per one million parts of inventiveethylene-based polymer compositions. The compounded inventiveethylene-based polymer compositions may further comprise from about 300to about 1250 parts of calcium stearate per one million parts ofinventive ethylene-based polymer compositions

Uses

The inventive ethylene-based polymer compositions may be employed in avariety of conventional thermoplastic fabrication processes to produceuseful articles, including objects comprising at least one film layer,such as a monolayer film, or at least one layer in a multilayer filmprepared by cast, blown, calendared, or extrusion coating processes;molded articles, such as blow molded, injection molded, or rotomoldedarticles; extrusions; fibers; and woven or non-woven fabrics.Multi-layer films, preferably 3 layer films, are useful in theinvention, especially where the multi-layer film can be used in astretch hood application. Thermoplastic compositions comprising theinventive ethylene-based polymer compositions include blends with othernatural or synthetic materials, polymers, additives, reinforcing agents,ignition resistant additives, antioxidants, stabilizers, colorants,extenders, crosslinkers, blowing agents, and plasticizers.

Additives and adjuvants may be added to the inventive ethylene-basedpolymer compositions post-formation. Suitable additives include fillers,such as organic or inorganic particles, including clays, talc, titaniumdioxide, zeolites, powdered metals, organic or inorganic fibers,including carbon fibers, silicon nitride fibers, steel wire or mesh, andnylon or polyester cording, nano-sized particles, clays, and so forth;tackifiers, oil extenders, including paraffinic or napthelenic oils; andother natural and synthetic polymers, including other polymers that areor can be made according to the embodiment methods.

Blends and mixtures of the inventive ethylene-based polymer compositionswith other polyolefins may be performed. Suitable polymers for blendingwith the inventive ethylene-based polymer compositions includethermoplastic and non-thermoplastic polymers including natural andsynthetic polymers. Exemplary polymers for blending includepolypropylene, (both impact modifying polypropylene, isotacticpolypropylene, atactic polypropylene, and random ethylene/propylenecopolymers), various types of polyethylene, including high pressure,free-radical LDPE, Ziegler-Natta LLDPE, metallocene PE, includingmultiple reactor PE (“in reactor” blends of Ziegler-Natta PE andmetallocene PE, such as products disclosed in U.S. Pat. Nos. 6,545,088(Kolthammer, et al.); 6,538,070 (Cardwell, et al.); 6,566,446 (Parikh,et al.); 5,844,045 (Kolthammer, et al.); 5,869,575 (Kolthammer, et al.);and 6,448,341 (Kolthammer, et al.)), ethylene-vinyl acetate (EVA),ethylene/vinyl alcohol copolymers, polystyrene, impact modifiedpolystyrene, ABS, styrene/butadiene block copolymers and hydrogenatedderivatives thereof (SBS and SEBS), and thermoplastic polyurethanes.Homogeneous polymers such as olefin plastomers and elastomers, ethyleneand propylene-based copolymers (for example, polymers available underthe trade designation VERSIFY™ Plastomers & Elastomers (The Dow ChemicalCompany), SURPASS (Nova Chemicals), and VISTAMAXX™ (ExxonMobil ChemicalCo.)) can also be useful as components in blends comprising theinventive ethylene-based polymer compositions.

The inventive ethylene-based polymer compositions maybe employed as asealant resins. Surprisingly, certain short chain branching distribution(SCBD), as shown by CDC, in combination with certain MWD, and a certainlevel of long chain branching (LCB) has shown to improve hot tack andheat seal performance, including increased hot-tack & heat-sealstrength, lower heat seal and hot tack initiation temperatures, and abroadening of the hot tack window. The ethylenic polymer maybe employedas a pipe and tubing resin through an optimization of the SCBD and MWD,with low unsaturation levels for improved ESCR (environmental stresscrack resistance) and higher PENT (Pennsylvania Edge-Notch TensileTest). The ethylenic polymer maybe employed in applications where UVstability, weatherability are desired through an optimization of theSCBD and MWD, in combination with low unsaturation levels, and lowlevels of low molecular weight, high commoner incorporated oligomers.The ethylenic polymer maybe employed in applications where low levels ofplate-out, blooming, die build-up, smoke formation, extractables, taste,and odor are desired through an optimization of the SCBD and MWD withlow levels of low molecular weight, high comonomer incorporatedoligomers. The ethylenic polymer maybe employed in stretch filmapplications. Surprisingly, certain SCBD, in combination with certainMWD, and a certain level of long chain branching (LCB) shows improvedstretchability and dynamic puncture resistance.

DEFINITIONS

The term “composition,” as used, includes a mixture of materials whichcomprise the composition, as well as reaction products and decompositionproducts formed from the materials of the composition.

The terms “blend” or “polymer blend,” as used, mean an intimate physicalmixture (that is, without reaction) of two or more polymers. A blend mayor may not be miscible (not phase separated at molecular level). A blendmay or may not be phase separated. A blend may or may not contain one ormore domain configurations, as determined from transmission electronspectroscopy, light scattering, x-ray scattering, and other methodsknown in the art. The blend may be effected by physically mixing the twoor more polymers on the macro level (for example, melt blending resinsor compounding) or the micro level (for example, simultaneous formingwithin the same reactor).

The term “linear” refers to polymers where the polymer backbone of thepolymer lacks measurable or demonstrable long chain branches, forexample, the polymer can be substituted with an average of less than0.01 long branch per 1000 carbons.

The term “polymer” refers to a polymeric compound prepared bypolymerizing monomers, whether of the same or a different type. Thegeneric term polymer thus embraces the term “homopolymer,” usuallyemployed to refer to polymers prepared from only one type of monomer,and the term “interpolymer” as defined. The terms “ethylene/α-olefinpolymer” is indicative of interpolymers as described.

The term “interpolymer” refers to polymers prepared by thepolymerization of at least two different types of monomers. The genericterm interpolymer includes copolymers, usually employed to refer topolymers prepared from two different monomers, and polymers preparedfrom more than two different types of monomers.

The term “ethylene-based polymer” refers to a polymer that contains morethan 50 mole percent polymerized ethylene monomer (based on the totalamount of polymerizable monomers) and, optionally, may contain at leastone comonomer.

The term “ethylene/α-olefin interpolymer” refers to an interpolymer thatcontains more than 50 mole percent polymerized ethylene monomer (basedon the total amount of polymerizable monomers) and at least oneα-olefin.

Examples

The following examples illustrate the present invention but are notintended to limit the scope of the invention. The examples of theinstant invention demonstrate improved elastic recovery while improvingmachine direction Elmendorf Tear and Dart B as well.

Resin Production

All raw materials (ethylene, 1-octene) and the process solvent (a narrowboiling range high-purity isoparaffinic solvent trademarked Isopar E andcommercially available from Exxon Mobil Corporation) are purified withmolecular sieves before introduction into the reaction environment.Hydrogen is supplied in pressurized cylinders as a high purity grade andis not further purified. The reactor monomer feed (ethylene) stream ispressurized via mechanical compressor to above reaction pressure at 750psig. The solvent and comonomer (1-octene) feed is pressurized viamechanical positive displacement pump to above reaction pressure at 750psig. The individual catalyst components are manually batch diluted tospecified component concentrations with purified solvent (Isopar E) andpressured to above reaction pressure at 750 psig. All reaction feedflows are measured with mass flow meters and independently controlledwith computer automated valve control systems.

The continuous solution polymerization reactors consist of two liquidfull, non-adiabatic, isothermal, circulating, and independentlycontrolled loops operating in a series configuration. Each reactor hasindependent control of all fresh solvent, monomer, comonomer, hydrogen,and catalyst component feeds. The combined solvent, monomer, comonomerand hydrogen feed to each reactor is independently temperaturecontrolled to anywhere between 5° C. to 50° C. and typically 40° C. bypassing the feed stream through a heat exchanger. The fresh comonomerfeed to the polymerization reactors can be manually aligned to addcomonomer to one of three choices: the first reactor, the secondreactor, or the common solvent and then split between both reactorsproportionate to the solvent feed split. The total fresh feed to eachpolymerization reactor is injected into the reactor at two locations perreactor roughly with equal reactor volumes between each injectionlocation. The fresh feed is controlled typically with each injectorreceiving half of the total fresh feed mass flow. The catalystcomponents are injected into the polymerization reactor throughspecially designed injection stingers and are each separately injectedinto the same relative location in the reactor with no contact timeprior to the reactor. The primary catalyst component feed is computercontrolled to maintain the reactor monomer concentration at a specifiedtarget. The two cocatalyst components are fed based on calculatedspecified molar ratios to the primary catalyst component. Immediatelyfollowing each fresh injection location (either feed or catalyst), thefeed streams are mixed with the circulating polymerization reactorcontents with Kenics static mixing elements. The contents of eachreactor are continuously circulated through heat exchangers responsiblefor removing much of the heat of reaction and with the temperature ofthe coolant side responsible for maintaining isothermal reaction

environment at the specified temperature. Circulation around eachreactor loop is provided by a screw pump. The effluent from the firstpolymerization reactor (containing solvent, monomer, comonomer,hydrogen, catalyst components, and molten polymer) exits the firstreactor loop and passes through a control valve (responsible formaintaining the pressure of the first reactor at a specified target) andis injected into the second polymerization reactor of similar design. Asthe stream exits the reactor it is contacted with water to stop thereaction. In addition, various additives such as anti-oxidants, can beadded at this point. The stream then goes through another set of Kenicsstatic mixing elements to evenly disperse the catalyst kill andadditives.

Following additive addition, the effluent (containing solvent, monomer,comonomer, hydrogen, catalyst components, and molten polymer) passesthrough a heat exchanger to raise the stream temperature in preparationfor separation of the polymer from the other lower boiling reactioncomponents. The stream then enters a two stage separation anddevolatization system where the polymer is removed from the solvent,hydrogen, and unreacted monomer and comonomer. The recycled stream ispurified before entering the reactor again. The separated anddevolatized polymer melt is pumped through a die specially designed forunderwater pelletization, cut into uniform solid pellets, dried, andtransferred into a hopper. After validation of initial polymerproperties the solid polymer pellets are manually dumped into a box forstorage. Each box typically holds ˜1200 pounds of polymer pellets.

The non-polymer portions removed in the devolatilization step passthrough various pieces of equipment which separate most of the ethylenewhich is removed from the system to a vent destruction unit (it isrecycled in manufacturing units). Most of the solvent is recycled backto the reactor after passing through purification beds. This solvent canstill have unreacted co-monomer in it that is fortified with freshco-monomer prior to re-entry to the reactor. This fortification of theco-monomer is an essential part of the product density control method.This recycle solvent can still have some hydrogen which is thenfortified with fresh hydrogen to achieve the polymer molecular weighttarget. A very small amount of solvent leaves the system as a co-productdue to solvent carrier in the catalyst streams and a small amount ofsolvent that is part of commercial grade co-monomers.

Inventive Ethylene-Based Polymer Compositions Inventive Example 1

Inventive ethylene-based polymer compositions, i.e. Inventive Example 1,is prepared according to the above procedure. Inventive Example 1 wastested for various properties according to the test methods describedbelow, and these properties are reported in Tables 2 and Tables 4-7. TheTable 1 and 1a-1d summarize the conditions for polymerization for theInventive Example 1.

Resin A Specifications (Composition for Skin Layers of the InventiveFilms 1 and 2)

Resin A has a target melt index of 0.8 dg/min and a target density of0.912 g/cc. It is produced in a dual reactor solution process where aconstrained geometry catalyst is used in the first reactor and aZiegler-Natta catalyst is used in the second reactor. Table 3 reportsthe melt index, density and % polymer split for the two reactors used tomake Resin A.

Film Fabrication

Alpine seven layer blown film line was used to produce 3 layerco-extruded films comprising 2 skin layers (layers 1 and 7,respectively) each comprising a single layer having a thickness ofapproximately 20 percent by volume, based on the total volume of the 3layer co-extruded film, and one core layer derived from five singlelayers (layers 2-6) having a total thickness of approximately 60 percentby volume, based on the total volume of the 3 layer co-extruded film.The blown film line consists of seven groove fed extruders with singleflight screws (all 50 mm). The length/diameter (L/D) ratio for allscrews is 30:1. The blown film line has a 250 mm die with dual lip airring cooling system, with a screen pack configuration of 20:40:60:80:20mesh and is equipped with internal bubble cooling system. Extruders 1and 7 feed into skin layers on either side of the co-extruded film andextruders 2, 3, 4, 5 and 6 feed into the core layer of the 3-layer film.All films are produced at 4 mil thickness.

Extrusion Data—Inventive Film 1

Extruders 1 and 7 contained 93.5 wt % of Resin A, 5 wt % of antiblockmaster batch as described below, 1.5 wt % of slip master batch and 0.5wt % of process aid master batch. Extruders 2 through 6 contained 98.5wt % of inventive polymer (Inventive Examples 1), 1 wt % of slip masterbatch and 0.5 wt % of process aid masterbatch. The fabricationconditions are reported in Tables 8, 8a, and 8b.

Process aid masterbatch, Ingenia AC-0101, available from IngeniaPolymers, comprises 8% by weight of a process aid;

Anti-block masterbatch, AMPACET 10063, available from Amapcet Corp,comprises 20% by weight of an anti-block agent; and

Slip masterbatch, AMPACET 10090, available from Amapcet Corp, comprises5% by weight of a slip agent.

Extrusion Data—Inventive Film 2

Extruders 1 and 7 contained 93.5 wt % of resin A, 5 wt % of antiblockmaster batch, 1.5 wt % of slip master batch and 0.5 wt % of process aidmaster batch. Extruders 2 through 6 contained 98.5 wt % of inventivepolymer (Inventive Example 1), 1 wt % of slip master batch and 0.5 wt %of process aid masterbatch. The fabrication conditions are reported inTables 9, 9a, and 9b.

Process aid masterbatch, Ingenia AC-0101, available from IngeniaPolymers, comprises 8% by weight of a process aid;

Anti-block masterbatch, AMPACET 10063, available from Amapcet Corp,comprises 20% by weight of an anti-block agent; and

Slip masterbatch, AMPACET 10090, available from Amapcet Corp, comprises5% by weight of a slip agent.

Extrusion Data—Comparative Film 1

Extruders 1 and 7 contained 98.12 wt % of a 1.0 melt index, 0.918 g/cm³density metallocene polyethylene, 1.38 wt % of antiblock master batch,and 0.5 wt % of process aid master batch. Extruders 2 through 6contained 99.5 wt % of a 0.5 melt index, approximately 0.930 g/ccdensity, 7.5% by wt of units derived from VA in the ethylene vinylacetate copolymer and 0.5 wt % of process aid masterbatch. Thefabrication conditions are reported in Tables 10, 10a, and 10b.

Process aid masterbatch, Ingenia AC-0101, available from IngeniaPolymers, comprises 8% by weight of a process aid;

Anti-block masterbatch, AMPACET 10063, available from Amapcet Corp,comprises 20% by weight of an anti-block agent; and

Slip masterbatch, AMPACET 10090, available from Amapcet Corp, comprises5% by weight of a slip agent.

Extrusion Data—Comparative 2

Extruders 1 and 7 contained 98.12 wt % of a 1.0 melt index, 0.918 g/ccdensity metallocene polyethylene, 1.38 wt % of antiblock master batch,and 0.5 wt % of process aid master batch. Extruders 2 through 6contained 99.5 wt % of a 0.5 melt index, approximately 0.930 g/ccdensity, 7.5% by wt of units derived from VA in the ethylene vinylacetate copolymer and 0.5 wt % of process aid masterbatch. Thefabrication conditions are reported in Tables 11, 11a, and 11b.

Process aid masterbatch, Ingenia AC-0101, available from IngeniaPolymers, comprises 8% by weight of a process aid;

Anti-block masterbatch, AMPACET 10063, available from Amapcet Corp,comprises 20% by weight of an anti-block agent; and

Slip masterbatch, AMPACET 10090, available from Amapcet Corp, comprises5% by weight of a slip agent.

The inventive films 1 and 2 and comparative films 1 and 2 are tested fortheir various properties according to the test methods described belowand these properties are reported in Table 12.

Test Methods Density

Samples that are measured for density are prepared according to ASTM D1928. Measurements are made within one hour of sample pressing usingASTM D792, Method B.

Melt Index

Melt index, or I₂, is measured in accordance with ASTM D 1238, Condition190° C./2.16 kg, and is reported in grams eluted per 10 minutes. I₁₀ ismeasured in accordance with ASTM D 1238, Condition 190° C./10 kg, and isreported in grams eluted per 10 minutes.

Differential Scanning Calorimetry (DSC)

Baseline calibration of the TA Instrument's DSC Q1000 is performed byusing the calibration wizard in the software. First, a baseline isobtained by heating the cell from −80° C. to 280° C. without any samplein the aluminum DSC pan. After that, sapphire standards are usedaccording to the instructions in the wizard. Then about 1-2 mg of afresh indium sample is analyzed by heating the sample to 180° C.,cooling the sample to 120° C. at a cooling rate of 10° C./min followedby keeping the sample isothermally at 120° C. for 1 minute, followed byheating the sample from 120° C. to 180° C. at a heating rate of 10°C./min. The heat of fusion and the onset of melting of the indium sampleare determined and checked to be within 0.5° C. from 156.6° C. for theonset of melting and within 0.5 J/g from 28.71 J/g for the heat offusion. Then deionized water is analyzed by cooling a small drop offresh sample in the DSC pan from 25° C. to −30° C. at a cooling rate of10° C./min. The sample is kept isothermally at −30° C. for 2 minutes andheated to 30° C. at a heating rate of 10° C./min. The onset of meltingis determined and checked to be within 0.5° C. from 0° C.

Samples of polymer are pressed into a thin film at a temperature of 350°F. About 5 to 8 mg of sample is weighed out and placed in a DSC pan. Alid is crimped on the pan to ensure a closed atmosphere. The sample panis placed in the DSC cell and then heated at a high rate of about 100°C./min to a temperature at least 30° C. above the polymer melttemperature, or 180° C. The sample is kept at this temperature for about5 minutes. Then the sample is cooled at a rate of 10° C./min to a least50° C. below the crystallization temperature, or −40° C., and keptisothermally at that temperature for 5 minutes. The sample is thenheated at a rate of 10° C./min until melting is complete. The resultingenthalpy curves are analyzed. The cool curve heat of fusion (J/g) iscalculated by integrating from the beginning of crystallization to −20°C. The second heating curve heat of fusion (J/g) is calculated byintegrating from −20° C. to the end of melting. Additionally, aperpendicular to the X axis (temperature axis) placed at 115° C., toidentify the area (J/g) before and after the drop as illustrated in FIG.25.

Gel Permeation Chromatography (GPC)

The GPC system consists of a Waters (Milford, Mass.) 150 C hightemperature chromatograph (other suitable high temperatures GPCinstruments include Polymer Laboratories (Shropshire, UK) Model 210 andModel 220) equipped with an on-board differential refractometer (RI).Additional detectors can include an IR4 infra-red detector from PolymerChAR (Valencia, Spain), Precision Detectors (Amherst, Mass.) 2-anglelaser light scattering detector Model 2040, and a Viscotek (Houston,Tex.) 150R 4-capillary solution viscometer. A GPC with the last twoindependent detectors and at least one of the first detectors issometimes referred to as “3D-GPC”, while the term “GPC” alone generallyrefers to conventional GPC. Depending on the sample, either the15-degree angle or the 90-degree angle of the light scattering detectoris used for calculation purposes. Data collection is performed usingViscotek TriSEC software, Version 3, and a 4-channel Viscotek DataManager DM400. The system is also equipped with an on-line solventdegassing device from Polymer Laboratories (Shropshire, UK). Suitablehigh temperature GPC columns can be used such as four 30 cm long ShodexHT803 13 micron columns or four 30 cm Polymer Labs columns of 20-micronmixed-pore-size packing (MixA LS, Polymer Labs). The sample carouselcompartment is operated at 140° C. and the column compartment isoperated at 150° C. The samples are prepared at a concentration of 0.1grams of polymer in 50 milliliters of solvent. The chromatographicsolvent and the sample preparation solvent contain 200 ppm of butylatedhydroxytoluene (BHT). Both solvents are sparged with nitrogen. Thepolyethylene samples are gently stirred at 160° C. for four hours. Theinjection volume is 200 microliters. The flow rate through the GPC isset at 1 ml/minute.

The GPC column set is calibrated before running the Examples by runningtwenty-one narrow molecular weight distribution polystyrene standards.The molecular weight (MW) of the standards ranges from 580 to 8,400,000grams per mole, and the standards are contained in 6 “cocktail”mixtures. Each standard mixture has at least a decade of separationbetween individual molecular weights. The standard mixtures arepurchased from Polymer Laboratories (Shropshire, UK). The polystyrenestandards are prepared at 0.025 g in 50 mL of solvent for molecularweights equal to or greater than 1,000,000 grams per mole and 0.05 g in50 ml of solvent for molecular weights less than 1,000,000 grams permole. The polystyrene standards were dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene M_(w) using the Mark-Houwink K and a(sometimes referred to as a) values mentioned later for polystyrene andpolyethylene. See the Examples section for a demonstration of thisprocedure.

With 3D-GPC absolute weight average molecular weight (“M_(w, Abs)”) andintrinsic viscosity are also obtained independently from suitable narrowpolyethylene standards using the same conditions mentioned previously.These narrow linear polyethylene standards may be obtained from PolymerLaboratories (Shropshire, UK; Part No.'s PL2650-0101 and PL2650-0102).The systematic approach for the determination of multi-detector offsetsis performed in a manner consistent with that published by Balke,Mourey, et al. (Mourey and Balke, Chromatography Polym., Chapter 12,(1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, ChromatographyPolym., Chapter 13, (1992)), optimizing triple detector log (M_(w) andintrinsic viscosity) results from Dow 1683 broad polystyrene (AmericanPolymer Standards Corp.; Mentor, Ohio) or its equivalent to the narrowstandard column calibration results from the narrow polystyrenestandards calibration curve. The molecular weight data, accounting fordetector volume off-set determination, are obtained in a mannerconsistent with that published by Zimm (Zimm, B. H., J. Chem. Phys., 16,1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scatteringfrom Polymer Solutions, Elsevier, Oxford, N.Y. (1987)). The overallinjected concentration used in the determination of the molecular weightis obtained from the mass detector area and the mass detector constantderived from a suitable linear polyethylene homopolymer, or one of thepolyethylene standards. The calculated molecular weights are obtainedusing a light scattering constant derived from one or more of thepolyethylene standards mentioned and a refractive index concentrationcoefficient, do/dc, of 0.104. Generally, the mass detector response andthe light scattering constant should be determined from a linearstandard with a molecular weight in excess of about 50,000 daltons. Theviscometer calibration can be accomplished using the methods describedby the manufacturer or alternatively by using the published values ofsuitable linear standards such as Standard Reference Materials (SRM)1475a, 1482a, 1483, or 1484a. The chromatographic concentrations areassumed low enough to eliminate addressing 2^(nd) viral coefficienteffects (concentration effects on molecular weight).

g′ by 3D-GPC

The index (g′) for the sample polymer is determined by first calibratingthe light scattering, viscosity, and concentration detectors describedin the Gel Permeation Chromatography method supra with SRM 1475ahomopolymer polyethylene (or an equivalent reference). The lightscattering and viscometer detector offsets are determined relative tothe concentration detector as described in the calibration. Baselinesare subtracted from the light scattering, viscometer, and concentrationchromatograms and integration windows are then set making certain tointegrate all of the low molecular weight retention volume range in thelight scattering and viscometer chromatograms that indicate the presenceof detectable polymer from the refractive index chromatogram. A linearhomopolymer polyethylene is used to establish a Mark-Houwink (MH) linearreference line by injecting a broad molecular weight polyethylenereference such as SRM1475a standard, calculating the data file, andrecording the intrinsic viscosity (IV) and molecular weight (M_(w)),each derived from the light scattering and viscosity detectorsrespectively and the concentration as determined from the RI detectormass constant for each chromatographic slice. For the analysis ofsamples the procedure for each chromatographic slice is repeated toobtain a sample Mark-Houwink line. Note that for some samples the lowermolecular weights, the intrinsic viscosity and the molecular weight datamay need to be extrapolated such that the measured molecular weight andintrinsic viscosity asymptotically approach a linear homopolymer GPCcalibration curve. To this end, many highly-branched ethylene-basedpolymer samples require that the linear reference line be shiftedslightly to account for the contribution of short chain branching beforeproceeding with the long chain branching index (g′) calculation.

A g-prime (g_(i)′) is calculated for each branched samplechromatographic slice (i) and measuring molecular weight (M_(i))according to Equation 7 (FIG. 3):where the calculation utilizes the IV_(linear reference,j) at equivalentmolecular weight, M_(j), in the linear reference sample. In other words,the sample IV slice (i) and reference IV slice (j) have the samemolecular weight (M_(i)=M_(j)). For simplicity, theIV_(linear reference,j) slices are calculated from a fifth-orderpolynomial fit of the reference Mark-Houwink Plot. The IV ratio, or isonly obtained at molecular weights greater than 3,500 because ofsignal-to-noise limitations in the light scattering data. The number ofbranches along the sample polymer (B_(n)) at each data slice (i) can bedetermined by using Equation 8 (FIG. 4), assuming a viscosity shieldingepsilon factor of 0.75:

Finally, the average LCBf quantity per 1000 carbons in the polymeracross all of the slices (i) can be determined using Equation 9 (FIG.5):

gpcBR Branching Index by 3D-GPC

In the 3D-GPC configuration the polyethylene and polystyrene standardscan be used to measure the Mark-Houwink constants, K and a areindependently for each of the two polymer types, polystyrene andpolyethylene. These can be used to refine the Williams and Wardpolyethylene equivalent molecular weights in application of thefollowing methods.

The gpcBR branching index is determined by first calibrating the lightscattering, viscosity, and concentration detectors as describedpreviously. Baselines are then subtracted from the light scattering,viscometer, and concentration chromatograms. Integration windows arethen set to ensure integration of all of the low molecular weightretention volume range in the light scattering and viscometerchromatograms that indicate the presence of detectable polymer from therefractive index chromatogram. Linear polyethylene standards are thenused to establish polyethylene and polystyrene Mark-Houwink constants asdescribed previously. Upon obtaining the constants, the two values areused to construct two linear reference conventional calibrations (“cc”)for polyethylene molecular weight and polyethylene intrinsic viscosityas a function of elution volume, as shown in Equations 10 and 11 (FIGS.6 & 7).

The gpcBR branching index is a robust method for the characterization oflong chain branching. See Yau, Wallace W., “Examples of Using3D-GPC—TREF for Polyolefin Characterization”, Macromol. Symp., 2007,257, 29-45. The index avoids the slice-by-slice 3D-GPC calculationstraditionally used in the determination of g′ values and branchingfrequency calculations in favor of whole polymer detector areas and areadot products. From 3D-GPC data, one can obtain the sample bulk M_(w) bythe light scattering (LS) detector using the peak area method. Themethod avoids the slice-by-slice ratio of light scattering detectorsignal over the concentration detector signal as required in the g′determination.

The area calculation in Equation 12 (FIG. 8) offers more precisionbecause as an overall sample area it is much less sensitive to variationcaused by detector noise and GPC settings on baseline and integrationlimits. More importantly, the peak area calculation is not affected bythe detector volume offsets. Similarly, the high-precision sampleintrinsic viscosity (IV) is obtained by the area method shown inEquation 13 (FIG. 9):

where DP_(i) stands for the differential pressure signal monitoreddirectly from the online viscometer.

To determine the gpcBR branching index, the light scattering elutionarea for the sample polymer is used to determine the molecular weight ofthe sample. The viscosity detector elution area for the sample polymeris used to determine the intrinsic viscosity (IV or [η]) of the sample.

Initially, the molecular weight and intrinsic viscosity for a linearpolyethylene standard sample, such as SRM1475a or an equivalent, aredetermined using the conventional calibrations for both molecular weightand intrinsic viscosity as a function of elution volume, per Equations14 and 15 (FIGS. 10 and 11):

Equation 16 (FIG. 12) is used to determine the gpcBR branching index:

where [η] is the measured intrinsic viscosity, [η]_(cc) is the intrinsicviscosity from the conventional calibration, M_(w) is the measuredweight average molecular weight, and M_(w,cc) is the weight averagemolecular weight of the conventional calibration. The Mw by lightscattering (LS) using Equation (12), FIG. 8, is commonly referred to asthe absolute Mw; while the M_(w,cc) from Equation (14), FIG. 10, usingthe conventional GPC molecular weight calibration curve is oftenreferred to as polymer chain Mw. All statistical values with the “cc”subscript are determined using their respective elution volumes, thecorresponding conventional calibration as previously described, and theconcentration (C_(i)) derived from the mass detector response. Thenon-subscripted values are measured values based on the mass detector,LALLS, and viscometer areas. The value of K_(PE) is adjusted iterativelyuntil the linear reference sample has a gpcBR measured value of zero.For example, the final values for and Log K for the determination ofgpcBR in this particular case are 0.725 and −3.355, respectively, forpolyethylene, and 0.722 and −3.993 for polystyrene, respectively.

Once the K and α values have been determined, the procedure is repeatedusing the branched samples. The branched samples are analyzed using thefinal Mark-Houwink constants as the best “cc” calibration values andapplying Equations 12-16, FIG. 8-12.

The interpretation of gpcBR is straight forward. For linear polymers,gpcBR calculated from Equation 16, FIG. 12, will be close to zero sincethe values measured by LS and viscometry will be close to theconventional calibration standard. For branched polymers, gpcBR will behigher than zero, especially with high levels of LCB, because themeasured polymer M_(w) will be higher than the calculated M_(w,cc), andthe calculated IV_(cc) will be higher than the measured polymer IV. Infact, the gpcBR value represents the fractional IV change due themolecular size contraction effect as the result of polymer branching. AgpcBR value of 0.5 or 2.0 would mean a molecular size contraction effectof IV at the level of 50% and 200%, respectively, versus a linearpolymer molecule of equivalent weight.

For these particular Examples, the advantage of using gpcBR incomparison to the g′ index and branching frequency calculations is dueto the higher precision of gpcBR. All of the parameters used in thegpcBR index determination are obtained with good precision and are notdetrimentally affected by the low 3D-GPC detector response at highmolecular weight from the concentration detector. Errors in detectorvolume alignment also do not affect the precision of the gpcBR indexdetermination. In other particular cases, other methods for determiningM_(w) moments may be preferable to the aforementioned technique.

CEF Method

Comonomer distribution analysis is performed with CrystallizationElution Fractionation (CEF) (PolymerChar in Spain) (B. Monrabal et al,Macromol. Symp. 257, 71-79 (2007)). Ortho-dichlorobenzene (ODCB) with600 ppm antioxidant butylated hydroxytoluene (BHT) is used as thesolvent. Sample preparation is done with autosampler at 160° C. for 2hours under shaking at 4 mg/ml (unless otherwise specified). Theinjection volume is 300 μl. The temperature profile of the CEF is:crystallization at 3° C./min from 110° C. to 30° C., thermal equilibriumat 30° C. for 5 minutes, elution at 3° C./min from 30° C. to 140° C. Theflow rate during crystallization is at 0.052 ml/min. The flow rateduring elution is at 0.50 ml/min. The data is collected at one datapoint/second.

The CEF column is packed by the Dow Chemical Company with glass beads at125 um±6% (MO-SCI Specialty Products) with ⅛ inch stainless tubing.Glass beads are acid washed by MO-SCI Specialty with the request fromthe Dow Chemical Company. Column volume is 2.06 ml. Column temperaturecalibration is performed by using a mixture of NIST Standard ReferenceMaterial Linear polyethylene 1475a (1.0 mg/ml) and Eicosane (2 mg/ml) inODCB. The temperature is calibrated by adjusting the elution heatingrate so that NIST linear polyethylene 1475a has a peak temperature at101.0° C., and Eicosane has a peak temperature of 30.0° C. The CEFcolumn resolution is calculated with a mixture of NIST linearpolyethylene 1475a (1.0 mg/ml) and hexacontane (Fluka, purum, ≧97.0%, 1mg/ml). A baseline separation of hexacontane and NIST polyethylene 1475ais achieved. The area of hexacontane (from 35.0 to 67.0° C.) to the areaof NIST 1475a from 67.0 to 110.0° C. is 50 to 50, the amount of solublefraction below 35.0° C. is <1.8 wt %. The CEF column resolution isdefined in FIG. 13 where the column resolution is 6.0.

CDC Method

Comonomer distribution constant (CDC) is calculated from comonomerdistribution profile by CEF. CDC is defined as Comonomer DistributionIndex divided by Comonomer Distribution Shape Factor multiplying by 100(Equation 1, FIG. 1)

Comonomer distribution index stands for the total weight fraction ofpolymer chains with the comonomer content ranging from 0.5 of mediancomonomer content (C_(median)) and 1.5 of C_(median) from 35.0 to 119.0°C. Comonomer Distribution Shape Factor is defined as a ratio of the halfwidth of comonomer distribution profile divided by the standarddeviation of comonomer distribution profile from the peak temperature(Tp).

CDC is calculated from comonomer distribution profile by CEF, and CDC isdefined as Comonomer Distribution Index divided by ComonomerDistribution Shape Factor multiplying by 100 as shown in Equation 1,FIG. 1, and wherein Comonomer distribution index stands for the totalweight fraction of polymer chains with the comonomer content rangingfrom 0.5 of median comonomer content (C_(median)) and 1.5 of C_(median)from 35.0 to 119.0° C., and wherein Comonomer Distribution Shape Factoris defined as a ratio of the half width of comonomer distributionprofile divided by the standard deviation of comonomer distributionprofile from the peak temperature (Tp).

CDC is calculated according to the following steps:

(A) Obtain a weight fraction at each temperature (T) (w_(T)(T)) from35.0° C. to 119.0° C. with a temperature step increase of 0.200° C. fromCEF according to Equation 2, FIG. 14.

(B) Calculate the median temperature (T_(median)) at cumulative weightfraction of 0.500, according to (Equation 3, FIG. 15)

(C) Calculate the corresponding median comonomer content in mole %(C_(median)) at the median temperature (T_(median)) by using comonomercontent calibration curve according to (Equation 4, FIG. 16).

(D) Construct a comonomer content calibration curve by using a series ofreference materials with known amount of comonomer content, i.e., elevenreference materials with narrow comonomer distribution (mono-modalcomonomer distribution in CEF from 35.0 to 119.0° C.) with weightaverage Mw of 35,000 to 115,000 (measured via conventional GPC) at acomonomer content ranging from 0.0 mole % to 7.0 mole % are analyzedwith CEF at the same experimental conditions specified in CEFexperimental sections;

(E) Calculate comonomer content calibration by using the peaktemperature (T_(p)) of each reference material and its comonomercontent; The calibration is calculated from each reference material asshown in Equation 4 as shown in FIG. 4, wherein: R² is the correlationconstant;

(F) Calculate Comonomer Distribution Index from the total weightfraction with a comonomer content ranging from 0.5*C_(median) to1.5*C_(median), and if T_(median) is higher than 98.0° C., ComonomerDistribution Index is defined as 0.95;

(G) Obtain Maximum peak height from CEF comonomer distribution profileby searching each data point for the highest peak from 35.0° C. to119.0° C. (if the two peaks are identical, then the lower temperaturepeak is selected); half width is defined as the temperature differencebetween the front temperature and the rear temperature at the half ofthe maximum peak height, the front temperature at the half of themaximum peak is searched forward from 35.0° C., while the reartemperature at the half of the maximum peak is searched backward from119.0° C., in the case of a well defined bimodal distribution where thedifference in the peak temperatures is equal to or greater than the 1.1times of the sum of half width of each peak, the half width of theinventive ethylene-based polymer composition is calculated as thearithmetic average of the half width of each peak;

(H) Calculate the standard deviation of temperature (Stdev) according toEquation 5, FIG. 17.

An example of comonomer distribution profile is shown in FIG. 23.

Conventional GPC M_(w-gpc) Determination

To obtain Mw-gpc values, the chromatographic system consist of either aPolymer Laboratories Model PL-210 or a Polymer Laboratories Model PL-220equipped with a refractive index (RI) concentration detector. The columnand carousel compartments are operated at 140° C. Three PolymerLaboratories 10-1 μm Mixed-B columns are used with a solvent of1,2,4-trichlorobenzene. The samples are prepared at a concentration of0.1 g of polymer in 50 mL of solvent. The solvent used to prepare thesamples contain 200 ppm of the antioxidant butylated hydroxytoluene(BHT). Samples are prepared by agitating lightly for 4 hours at 160° C.The injection volume used is 100 microliters and the flow rate is 1.0mL/min. Calibration of the GPC column set is performed with twenty onenarrow molecular weight distribution polystyrene standards purchasedfrom Polymer Laboratories. The polystyrene standard peak molecularweights are converted to polyethylene molecular weights shown in FIG. 18where M is the molecular weight, A has a value of 0.4316 and B is equalto 1.0.

A third order polynomial is determined to build the logarithmicmolecular weight calibration as a function of elution volume. Theweight-average molecular weight by the above conventional calibration isdefined as Mw_(cc) in the equation shown in Equation 14 as shown in FIG.10. Where, the summation is across the GPC elution curve, with RI andM_(cc) represents the RI detector signal and conventional calibrationmolecular weight at each GPC elution slice. Polyethylene equivalentmolecular weight calculations are performed using Viscotek TriSECsoftware Version 3.0. The precision of the weight-average molecularweight ΔMw is excellent at <2.6%.

¹H NMR Method

3.26 g of stock solution is added to 0.133 g of polyolefin sample in 10mm NMR tube. The stock solution is a mixture of tetrachloroethane-d₂(TCE) and perchloroethylene (50:50, w:w) with 0.001M Cr³⁺. The solutionin the tube is purged with N₂ for 5 minutes to reduce the amount ofoxygen. The capped sample tube is left at room temperature overnight toswell the polymer sample. The sample is dissolved at 110° C. withshaking. The samples are free of the additives that may contribute tounsaturation, e.g. slip agents such as erucamide.

The ¹H NMR are run with a 10 mm cryoprobe at 120° C. on Bruker AVANCE400 MHz spectrometer. The pulse sequence is shown in Table below.

Two experiments are run to get the unsaturation: the control and thedouble presaturation experiments.

For the control experiment, the data is processed with exponentialwindow function with LB=1 Hz, baseline was corrected from 7 to −2 ppm.The signal from residual ¹H of TCE is set to 100, the integral I_(total)from −0.5 to 3 ppm is used as the signal from whole polymer in thecontrol experiment. The number of CH₂ group, NCH₂, in the polymer iscalculated as shown in FIG. 19.

For the double presaturation experiment, the data is processed withexponential window function with LB=1 Hz, baseline was corrected from6.6 to 4.5 ppm. The signal from residual ¹H of TCE is set to 100, thecorresponding integrals for unsaturations (I_(vinylene),I_(trisubstituted), I_(vinyl) and I_(vinylidene)) were integrated basedon the region shown in the following FIG. 2. The number of unsaturationunit for vinylene, trisubstituted, vinyl and vinylidene are calculated:

N _(vinylene) =I _(vinylene)/2

N _(trisubstituted) =d _(trisubstituted)

N _(vinyl) =I _(vinyl)/2

N _(vinylidene) =I _(vinylidene)/2

The unsaturation unit/1,000,000 carbons is calculated as following:

N _(vinylene)/1,000,000 C=(N _(vinylene)/NCH₂)*1,000,000

N _(trisubstituted)/1,000,000 C=(N _(trisubstituted)/NCH₂)*1,000,000

N _(vinyl)/1,000,000 C=(N _(vinyl)/NCH₂)*1,000,000

N _(vinylidene)/1,000,000 C=(N _(vinylidene)/NCH₂)*1,000,000

The requirement for unsaturation NMR analysis includes: level ofquantitation is 0.47±0.02/1,000,000 carbons for Vd2 with 200 scans (lessthan 1 hour data acquisition including time to run the controlexperiment) with 3.9 wt % of sample (for Vd2 structure, seeMacromolecules, vol. 38, 6988, 2005), 10 mm high temperature cryoprobe.The level of quantitation is defined as signal to noise ratio of 10.

The chemical shift reference is set at 6.0 ppm for the ¹H signal fromresidual proton from TCT-d2. The control is run with ZG pulse, TD 32768,NS 4, DS 12, SWH 10,000 Hz, AQ 1.64 s, D1 14 s. The double presaturationexperiment is run with a modified pulse sequence, O1P 1.354 ppm, O2P0.960 ppm, PL9 57 db, PL21 70 db, TD 32768, NS 200, DS 4, SWH 10,000 Hz,AQ 1.64 s, D1 1 s, D13 13 s. The modified pulse sequences forunsaturation with Bruker AVANCE 400 MHz spectrometer are shown in FIG.21.

Gel Content Gel content is determined in accordance to ASTM D2765-01Method A in xylene. The sample is cut to required size using a razorblade.

Film Testing Conditions

The following physical properties are measured on the films produced:

-   -   45° Gloss: ASTM D-2457.    -   MD and CD Elmendorf Tear Strength: ASTM D-1922.    -   MD and CD Tensile Strength: ASTM D-882.    -   Dart Impact Strength: ASTM D-1709.    -   Stretch hooder 100/75 test:

A film sample of dimensions 100 mm×25 mm and given thickness was usedfor the stretch hooder 100/75 test. The film sample was stretched to100% elongation at a speed of 1000 mm/min using Instron 5581 mechanicaltesting system. When 100% elongation was reached, film sample was keptin this position for 15 seconds and then returned back to 75% elongationat a speed of 1000 mm/min. After waiting at this elongation for 5minutes, load on the sample was measured and recorded as holding force.Afterwards, the Instron grips were returned to zero elongation and filmsample was removed. After 24 hours of waiting at ambient conditions,final length of the film was measured and permanent deformation wascalculated using the following equation.

${\% \mspace{14mu} {permanent}\mspace{14mu} {deformation}} = {\frac{{{final}\mspace{14mu} {length}} - {{initial}\mspace{14mu} {length}}}{{initial}\mspace{14mu} {length}} \times 100}$

Elastic recover was calculated as

Elastic recovery=100−permanent deformation

5 specimens were used for each sample and average values for holdingforce, permanent set and elastic recovery are reported.

-   -   Stretch hooder 60/40 test

This test is very similar to stretch hooder 100/75 test except thatinitially the film sample is stretched to 60% elongation at a speed of1000 mm/min, held there for 15 seconds and then returned to 40%elongation at same speed. Holding force was measured after waiting for 5minutes at 40% elongation. The procedure for measuring permanent set andelastic recovery are exactly the same as the stretch hooder 100/75 testmethod.

All applications, publications, patents, test procedures, and otherdocuments cited, including priority documents, are fully incorporated byreference to the extent such disclosure is not inconsistent with thedisclosed compositions and methods and for all jurisdictions in whichsuch incorporation is permitted.

The present invention may be embodied in other forms without departingfrom the spirit and the essential attributes thereof, and, accordingly,reference should be made to the appended claims, rather than to theforegoing specification, as indicating the scope of the invention.

TABLE 1 1. REACTOR FEEDS IE.. 1 Primary Reactor Feed Temperature (° C.)40.0 Primary Reactor Total Solvent Flow (lb/hr) 788 Primary ReactorFresh Ethylene Flow (lb/hr) 151 Primary Reactor Total Ethylene Flow(lb/hr) 158 Comonomer Type 1-octene Primary Reactor Fresh Comonomer Flow(lb/hr) 0.0 Primary Reactor Total Comonomer Flow (lb/hr) 14.6 PrimaryReactor Feed Solvent/Ethylene Ratio 5.22 Primary Reactor Fresh HydrogenFlow (sccm) 4474 Primary Reactor Hydrogen mole % 0.43 Secondary ReactorFeed Temperature (° C.) 40.2 Secondary Reactor Total Solvent Flow(lb/hr) 439.6 Secondary Reactor Fresh Ethylene Flow (lb/hr) 142.0Secondary Reactor Total Ethylene Flow (lb/hr) 145.8 Secondary ReactorFresh Comonomer Flow (lb/hr) 14.3 Secondary Reactor Total Comonomer Flow(lb/hr) 22.2 Secondary Reactor Feed Solvent/Ethylene Ratio 3.10Secondary Reactor Fresh Hydrogen Flow (sccm) 2223 Secondary ReactorHydrogen Mole % 0.234 Fresh Comonomer injection location SecondaryReactor Ethylene Split (wt %) 52.0

TABLE 1a Inventive Example 1 1. REACTOR FEED Units Avg. C2 feed split %59.13 Selected Octene Feed Point # Loop 1 Selected Octene Flow klbs/hr8.30 Octene to Polymer Ratio lb/lb 15.6 First Reactor Fresh EthyleneFlow klbs/hr 25.4 First Reactor Solvent to Ethylene ratio lb/lb 6.00First Reactor Solvent Flow klbs/hr 158.4 First Reactor Hydrogen Flowlbs/hr 6.4 First Reactor Mole % Hydrogen mol % 0.35 First Reactor FeedTemperature ° C. 12.3 Second Reactor Fresh Ethylene Flow klbs/hr 18.1Second Reactor Solvent to Ethylene ratio lb/lb 2.70 Second ReactorSolvent Flow klbs/hr 47.5 Second Reactor Hydrogen Flow lbs/hr 1.18Second Reactor Mole % Hydrogen mol % 0.092 Second Reactor FeedTemperature ° C. 12.0 Recycle Solvent FTnIR [C2] wt % 0.75 RecycleSolvent FTnIR [C8] wt % 6.68

TABLE 1b Inventive 2. REACTION Example 1 First Reactor FTnIR [C2] g/l17.88 First Reactor Tempered Water Inlet temp. ° C. 131.6 First ReactorSelected Temperature ° C. 140.1 First Reactor Loop Differential Pressurepsid 46.88 First Reactor 10Log Viscosity LogcP 2.950 First ReactorSolution Density g/cm3 0.6098 First Reactor Pump speed rpm 977 FirstReactor Residence time Min 10.15 First Reactor Recycle ratio — 7.58First Reactor low pressure feed ratio lb/lb 0.50 First Reactor Polymerconcentration wt % 13.43 First Reactor Ethylene conversion by FTnIR —79.48 Second Reactor FTnIR [C2] g/l 7.80 Second Reactor Tempered WaterInlet temp. ° C. 176.8 Second Reactor Selected Temperature ° C. 190.0Second Reactor Loop Differential Pressure psid 39.30 Second Reactor10Log Viscosity LogcP 2.840 Second Reactor Solution Density g/cm3 0.5988Second Reactor Pump speed rpm 1166 Second Reactor Residence time Min7.30 Second Reactor Recycle ratio — 6.51 Second Reactor low pressurefeed ratio lb/lb 0.09 Second Reactor Polymer concentration wt % 20.88Overall Ethylene conversion by FTnIR % 92.64 Overall Ethylene conversionby vent % 92.63 Ethylene vent mass flow lbs/hr 1441

TABLE 1c Inventive 3. CATALYST Example 1 First Reactor DOC-6114 flowlb/hr 7.87 First Reactor RIBS-2 flow lb/hr 6.37 First Reactor MMAO-3Aflow lb/hr 7.95 Second Reactor DOC-6114 flow lb/hr 54.64 Second ReactorRIBS-2 flow lb/hr 10.42 Second Reactor MMAO-3A flow lb/hr 14.76 FirstReactor DOC-6114 wt % DOC-6114 0.25 concentration First Reactor RIBS-2concentration wt % RIBS-2 0.50 First Reactor MMAO-3A (Al) wt % Al 0.10concentration Second Reactor DOC-6114 wt % DOC-6114 0.25 concentrationSecond Reactor RIBS-2 wt % RIBS-2 1.80 concentration Second ReactorMMAO-3A (Al) wt % Al 0.10 concentration First Reactor RIBS-2 to Zr ratioratio 1.42 First Reactor Aluminum to Zr ratio ratio 16.17 First ReactorCatalyst (Zr) efficiency M lbs poly/lb Zr 15.52 First Reactor RIBS-2efficiency M lbs poly/lb RIBS-2 0.83 Second Reactor RIBS-2 to Zr ratioratio 1.20 Second Reactor Aluminum to Zr ratio ratio 4.32 Second ReactorCatalyst (Zr) M lbs poly/lb Zr 2.23 efficiency Second Reactor RIBS-2efficiency M lbs poly/lb RIBS-2 0.14 Overall Catalyst (Zr) efficiency Mlbs poly/lb Zr 3.90 Overall RIBS-2 efficiency M lbs poly/lb RIBS-2 0.24

TABLE 1d Catalysts and catalyst components detailed nomenclature.Description CAS Name CAT-A Zirconium,[2,2″′-[1,3-propanediylbis(oxy-O)]bis[3″,5,5″-tris(1,1-dimethylethyl)-5′-methyl[1,1′:3′,1″-terphenyl]-2′-olato-O]]dimethyl-,(OC-6-33)- CAT-B[N-(1,1-dimethylethyl)-1,1-dimethyl-1-[(1,2,3,3a,8a-)-1,5,6,7-tetrahydro-2-methyl-s-indacen-1-yl]silanaminato(2-)-N][(1,2,3,4-)-1,3-pentadiene]- RIBS-2Amines, bis(hydrogenated tallow alkyl)methyl,tetrakis(pentafluorophenyl)borate(1-) MMAO-3A Aluminoxanes, iso-Bu Me,branched, cyclic and linear; modified methyl aluminoxane

TABLE 2 Melt Index, I₂ (lab) dg/min 0.79 I₁₀/I₂ (lab) Ratio 8.07 Density(lab) g/cm3 0.904 Polymer split in reactor 1 wt % 50

TABLE 3 Polymer Split Overall melt Oveall Overall reactor 1 (%) index(dg/min) I₁₀/I₂ Density (kg/m³) Resin A 54 0.8 8.3 912

TABLE 4 Unsaturation Unit/1,000,000 C. vinylene trisubstituted vinylvinylidene Total Inventive 16 7 55 12 90 Example 1

TABLE 5 Comonomer Standard Half Half CDC distribution Deviation, Width,Width/ (Comonomer Index ° C. ° C. Stdev Dist. Constant) Inventive 89.109.48 6.61 0.70 127.9 Example 1

TABLE 6 Cool Curve Data 2nd Heat Curve Data Crystallization Total Heatof Peak melting Total Heat of Heat of fusion temperature fusion-coolingpoint fusion-heating above 115° C. DSC Sample (° C.) (J/g) (° C.) (J/g)(J/g) Inventive 83.7 104.9 99.5 105.5 0.027 Example 1

TABLE 7 Conventional Conventional Conventional Conventional GPC GPC GPCGPC M_(n) (g/mole) M_(w) (g/mole) M_(z) (g/mole) M_(w)/M_(n) Inventive34,880 101,200 201,500 2.90 Example 1

TABLE 8 % of Melt Screw full temper- Melt Inventive speed load aturepressure Output Film 1 (RPM) current (° F.) (psi) Layer % (lb/hr)Extruder 1 49.3 59 467 6354 20 75 Extruder 2 42.1 53.3 473 5403 12 45Extruder 3 42.4 53.9 473 5678 12 45 Extruder 4 43.6 52.7 455 476 12 45Extruder 5 43.1 50 453 4257 12 45 Extruder 6 42.4 54.1 475 5506 12 45Extruder 7 49 58.8 462 7328 20 75

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 8a Actual Temperature profile (° F.) Extruder 1 Extruder 2Extruder 3 Extruder 4 Extruder 5 Extruder 6 Extruder 7 Zone 1 85.4 79.781.5 82.1 79.6 80.7 80 Zone 2 300.6 305.5 302.4 304.5 304.5 312.5 308Zone 3 379.6 380 379.8 380 379.2 381.1 380.1 Zone 4 379.8 379.9 380381.8 379.9 382.2 379.9 Zone 5 381.7 379.6 379.2 381 379.4 377.3 381.8Adapter 1 450 450.4 449.6 449.6 450 450.8 450.2 Adapter 2 451 455.6448.1 453.1 444.7 449.2 443.7 Adapter 3 450.4 452.2 447.8 450.6 449.7448.1 447.6

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 8b Die temperature 1 (° F.) 452.6 Blow up ratio 2.56 Die gap (mm)2 Die temperature 2 (° F.) 447.9 Frost line height 36 Nip speed (ft/min)49.9 Die temperature 3 (° F.) 449.5 Lay flat (inches) 39.58 Die diameter(mm) 250 Die temperature 4 (° F.) 449.8 left gusset (inches) 7.5 Dietemperature 5 (° F.) 450.2 right gusset (inches) 7.5 net layflat(inches) 24.58

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 9 % of Screw full Melt Melt Inventive speed load temperaturepressure Layer Output Film 2 (RPM) current (° F.) (psi) % (lb/hr)Extruder 1 49.7 59 466.4 6310 20 75 Extruder 2 42.3 53.9 468.8 5438 1245 Extruder 3 43.3 54.5 477.1 5752 12 45 Extruder 4 43 54.3 457 4768 1245 Extruder 5 45.3 51.6 458.8 4332 12 45 Extruder 6 42.2 54.7 477.8 554412 45 Extruder 7 48.8 58.8 467.3 7182 20 75

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 9a Actual Temperature profile (° F.) Extruder 1 Extruder 2Extruder 3 Extruder 4 Extruder 5 Extruder 6 Extruder 7 Zone 1 86.9 80.380.6 80.2 80.3 81 80.1 Zone 2 302.9 305.2 301.7 302 304.7 312.5 307.8Zone 3 380.1 380.3 380.6 380 380.7 381 379.8 Zone 4 380.4 379.7 379.5377.9 378.7 381.9 379.8 Zone 5 380.7 379.6 379.9 379.6 379.1 377.8 379.8Adapter 1 450.1 450.2 449.5 449 449.5 451 450 Adapter 2 447.6 445.8447.9 448.4 458.8 447.4 457.4 Adapter 3 449 448.4 449.5 450 450.5 449.1452.4

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 9b Die temperature 1 (° F.) 447 Blow up ratio 3.59 Die gap (mm) 2Die temperature 2 (° F.) 449.1 Frost line height 37 Nip speed (ft/min)35.6 Die temperature 3 (° F.) 449.2 Lay flat (inches) 55.67 Die diameter(mm) 250 Die temperature 4 (° F.) 449.4 left gusset (inches) 11.5 Dietemperature 5 (° F.) 449.2 right gusset (inches) 11.5 net layflat(inches) 32.67

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 10 Screw % of Melt Melt Comparative speed full load temperaturepressure Layer Output Film 1 (RPM) current (° F.) (psi) % (lb/hr)Extruder 1 45 63.3 473.4 7677 20 75 Extruder 2 30.9 48.9 455.9 4587 1245 Extruder 3 26.9 47.9 462.5 4647 12 45 Extruder 4 31.5 48.1 445.3 391112 45 Extruder 5 32.6 48.2 436.6 3583 12 45 Extruder 6 31.1 48.7 461.84513 12 45 Extruder 7 46.4 65.6 472.7 8658 20 75

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 10a Actual Temperature profile (° F.) Extruder 1 Extruder 2Extruder 3 Extruder 4 Extruder 5 Extruder 6 Extruder 7 Zone 1 85.6 81.780.3 82.6 80.5 82.5 80.3 Zone 2 380.6 380.4 379.5 380.2 380.1 380 380.3Zone 3 381.4 379.8 379.8 380.1 380 379.8 380.2 Zone 4 380.8 379.6 379.8379.9 379.9 379.5 379.7 Zone 5 380.7 380.1 379.8 380 380.1 380 379.3Adapter 1 451 450.1 449.6 450.1 449.8 450 449.8 Adapter 2 452.4 450.7441.7 461.4 442.1 443.1 445.6 Adapter 3 450.6 450.2 446.6 449.9 450.1447.2 448.1

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 10b Die temperature 1 (° F.) 449.4 Blow up ratio 2.56 Die gap (mm)2 Die temperature 2 (° F.) 449.4 Frost line height (inches) 35 Nip speed(ft/min) 49.2 Die temperature 3 (° F.) 448.7 Lay flat (inches) 39.58 Diediameter (mm) 250 Die temperature 4 (° F.) 449.6 left gusset (inches)7.5 Die temperature 5 (° F.) 449.4 right gusset (inches) 7.5 net layflat(inches) 24.58

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 11 % of Screw full Melt Melt Comparative speed load temperaturepressure Layer Output Film 2 (RPM) current (° F.) (psi) % (lb/hr)Extruder 1 45 64.5 476.2 7649 20 74.7 Extruder 2 31.1 48.9 455.4 4656 1245 Extruder 3 32.9 48.4 460.4 4853 12 45 Extruder 4 32 48.2 443.4 399612 45 Extruder 5 33.1 48.4 438.7 3616 12 45 Extruder 6 30.9 48.8 459.84556 12 45 Extruder 7 46.3 65.6 475.1 8667 20 75.3

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 11a Actual Temperature profile (° F.) Extruder 1 Extruder 2Extruder 3 Extruder 4 Extruder 5 Extruder 6 Extruder 7 Zone 1 86.1 80.481.7 82.8 80 82.6 80.1 Zone 2 380.4 380.2 379.9 380.4 380.2 380.5 380.2Zone 3 380 379.9 380 380 380 380.3 380.2 Zone 4 380.1 380 379.9 380.1380.1 379.7 379.7 Zone 5 378.9 380.2 380.1 380.3 380 380.1 380.1 Adapter1 449.9 450 450 450 449.9 450 449.8 Adapter 2 456 448.8 444.6 456.2449.9 444.4 450.6 Adapter 3 451.8 449.4 446.4 449.9 450.4 446.5 449.6

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 11b Die temperature 1 (° F.) 450.6 Blow up ratio 3.59 Die gap (mm)2 Die temperature 2 (° F.) 450.7 Frost line height (inches) 35 Nip speed(ft/min) 34.7 Die temperature 3 (° F.) 450.5 Lay flat (inches) 55.53 Diediameter (mm) 250 Die temperature 4 (° F.) 450.2 left gusset (inches)11.5 Die temperature 5 (° F.) 450.3 right gusset (inches) 11.5 netlayflat (inches) 32.53

All temperatures were measured at one point during the process, andmaintained at approximately the measured value±2° F.

TABLE 12 Film physical property data Sample Test Comparative 1Comparative 2 Example 1 Example 2 Stretch hooder-100/75 test AverageElastic Recovery (%) 41.8 42.4 46.4 47.0 Average Permanent Deformation(%) 58.2 57.6 53.6 53.0 Stretch hooder-60/40 test Average ElasticRecovery (%) 47.7 48.6 52.9 53.0 Average Permanent Deformation (%) 52.351.4 47.1 47.0 Average MD tear (g) 917 1143 1276   1403   AverageNormalized MD tear (g/mil) 229 286 319   351   Dart B (g) 1180 1410>1500*   >1500*   Dart B (g/mil) 295 352.5 >350   >350   Average-MDBreak Stress (psi) 4491 4698 6243   6384   Average-CD Break Stress (psi)4347 4440 6124   6172   *Maximum value that can be tested in dart B testis 1500 g

1. An article comprising a multi-layer film having a thickness of atleast 3 mils comprising at least one inner layer and two exteriorlayers, wherein the inner layer comprises at least 50 weight percentpolyethylene copolymer having a melt index less than 2 grams/10 minutes,a density less than or equal to 0.910 g/cm³, an total heat of fusionless than 120 Joules/gram and a heat of fusion above 115° C. of lessthan 5 Joules/gram, and a total heat of fusion of the inner layer isless than a heat of fusion of either of the two exterior layers, andwherein the multi-layer film has an elastic recovery of at least 40%when stretched to 100% elongation.
 2. The article of claim 1, whereinthe exterior layers are less than 50 weight percent of the total film.3. The article of claim 1 wherein the film has 3 layers and is madeusing a blown film process.
 4. The article of claim 1, wherein thearticle is a stretch hood film structure.
 5. The article of claim 1wherein the polyethylene copolymer in the inner layer has a M_(w)/M_(n)of at least 2.5.
 6. The article of claim 1 wherein the polyethylenecopolymer of the inner layer is characterized by a ComonomerDistribution Constant greater than about 45 and as high as 400, andwherein the polyethylene copolymer has less than 120 total unsaturationunit/1,000,000 C.
 7. The article of claim 1 wherein the polyethylenecopolymer of the inner layer is characterized by up to about 3 longchain branches/1000 carbons.
 8. The article of claim 1 wherein thepolyethylene copolymer of the inner layer is further characterized ascomprising less than 20 vinylidene unsaturation unit/1,000,000 C.
 9. Thearticle of claim 1 wherein the polyethylene copolymer of the inner layercomprises a single DSC melting peak.